British police say they have detained a 27-year-old man in connection with the failed July 21 bombings in the London transit system

Officials have not identified the man, but say he is suspected of a role in the attacks in which terrorists tried to set off bombs on three London subway trains and a bus, but the devices failed to explode.

Police say they are searching at least two homes in west London in connection with the investigation. Authorities are already holding five suspects in connection with the failed attacks.

The attacks came two weeks after four bombers set off explosives on London subway trains and a bus, killing themselves and 52 others.